王沿东
,
杨王玥
,
孙祖庆
,
陈国良
,
祝东
材料研究学报
本文研究了Ti_3Al 基和Ni_3Al 基合金室温下力学性能与裂纹扩展行为。研究结果表明:Ti_3Al 基合金主裂纹穿过母相,切过或绕过条状与块状α_2相,带有块状α_2组织的Ti_3Al 基合金次生裂纹大都起始及中止于α_2相界;Ni_3Al 基合金基体可以产生交滑移,滑移线中止于第二相NiAl 边界,最后于Ni_3Al/NiAl 相界处开裂;Ni_3Al 基合金增韧以裂纹转向与裂纹屏蔽为主,不同形态第二相对裂纹扩展阻力不同,其中长条状第二相扩展阻力大于短条状。Ti_3Al 基和Ni_3Al 基合金裂纹扩展行为可直接与其宏观力学性能相关联。
关键词:
金属间化合物
,
crack propagation
,
cross-slip
,
fracture toughness
WANG Liming ZHU Dong YAO Mei CAI Qigong ZOU Dunxu State Key Laboratory for Fatigue and Fracture of Materials
,
Academia Sinica
,
Shenyang
,
Central Iron and Steel Research Institute
,
Ministry of Metallurgical Industry
,
Beijing
,
China
金属学报(英文版)
Plastic deformation of TiAI and TiAI-V intermetallic compounds has been studied by com- pression experiment at various temperatures and strain rates.Results show that the plastic deformation in distinct temperature range is principally controlled by the mechanisms of Peierls-Nabarro,cross slip and creep of dislocations.For TiAI-V alloy deformed at a range of 600—700 K,the negative strain rate dependence of flow stress was observed,i.e.,the more the plastic strain is.the more the negative dependence will be.A possible mechanism of the anomaly could be interpreted by thermal activation of dislocation cross slipping.The effects of temperature and strain rate on work-hardening exponent were also studied and discussed.
关键词:
TiAl
,
null
,
null
,
null
ZHU Shijie YANG Zhian WANG Zhongguang State Key Laboratory for Fatigue and Fracture of Materials
,
Institute of Metal Research
,
Shenyang
,
110015
,
ChinaTo whom correspondence should be addressed
材料科学技术（英文）
Cyclic creep tests of Al-Mg alloy have been conducted at a wide range of stress and temperature.When Mg content is beyond 0.45%, the strain bursts can be observed in the cyclic creep curves.There exists a critical stress for the occur- rence of the strain burst,which increases with an in- crease of Mg content and is almost 60% of the ul- timate tensile stress.The occurrence of strain burst is proposed to be controlled by the easiness of the cross-slip of dislocations.For Al-Mg alloy,the dynamic strain aging plays an important role in the strain bursts.
关键词:
cyclic creep
,
null
,
null
,
null
